Haying machines are known having a frame from which is suspended a plurality of rotary rakes each having an annular array of tines. The rakes are rotated codirectionally or are counterrotated and their tines are usually limitedly oscillatable about axes extending generally radially to the respective axis of rotation of the respective rake. The inner end of each tine is provided with a control arm that rides on a cam fixed to a central axial shaft. This cam may be axially displaced along the shaft by rotation of this shaft.
In one known type of haying machine (see example German published specification No. 2,164,080) the function of a tedder and a windrower are combined. During windrowing the rotation axis is vertical and the tines extend horizontally. The tips of the tines thus describe paths or orbits which are parallel to the ground. Control of the tines is effected by means of arms carried on the tines which ride during windrowing on a cam. For tedding the cam is held out of engagement with control arms so that the tines, for example biased by means of return springs, are held in a position in which their ends are directed toward the ground. In addition for tedding the rotation axis of the device is tipped relative to the ground so that the plane defined by the tips of the tines lies at an angle to the ground. At the point at which this plane is closest to the ground the tine ends extend essentially perpendicular to the ground. It is also necessary for tedding that the orbits of neighboring rakes overlap one another. This is effected by relatively complicated mechanical arrangements that require considerable time and patience for changeover between windrowing and tedding operations.
Another type of combined tedder-windrower is known (see Austrian Pat. No. 298,867) in which the cam is vertically fixed relative to the collar in which the tines are fitted so that it is possible to increase the diameter of the orbits of the tines of each rotary rig by pivoting each tine about an axis passing through the tine and tangential to an imaginary cylinder centered on the rotation axis. When the rotary-rake axis is vertical the tines extend horizontally so that the control arms can be pulled out of contact with the cam, allowing the bent ends of the tines to swing up. This creates a slight increase in the diameter. In order to obtain the necessary overlapping between orbits of adjoining rakes it is nonetheless still necessary to provide complicated mechanism to shorten the frame length between rakes. If the axis of each rake is tipped then the ends of the tines extend substantially perpendicularly to the ground while the plane defined by the orbits of the ends of these tines lies at an angle to the ground. It is necessary to displace each tine separately into the necessary position so that changeover time from tedding to raking is very long.